| Co-Investigator(Kenkyū-buntansha) |
KAJIYAMA Mikio Faculty of Agriculture, The University of Tokyo, 農学部, 助手 (40191978)
TAKEMURA Akio Faculty of Agriculture, The University of Tokyo, 農学部, 助手 (50183455)
HATANO Yasunori Faculty of Agriculture, The University of Tokyo, 農学部, 助手 (70172921)
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| Research Abstract |
A variety of new wood-based materials have recently been industrially developed and they are going to be used in some structural applications, where mechanical durability of the materials is considered to be one of the most important factor. We have tried to compare the physical properties of adhesives and adhesive performances, including the durability of the bonded systems, and to analyse the results rheologically. Results are summarized below;
Dynamic mechanical properties of 3 PVAc-based adhesives, a polyester hot melt adhesive, 3 EVAc-based hot melt adhesives and an acrylic foam binder (VHB) are measured at 110Hz. Adhesive shear strength, adhesive tensile strength and peel strength are measured as a function of both temperature and deformation rate. Time-temperature superposition procedures are applied to the experimental data, and master curves are constructed. Adhesive shear strength has a maximum at the highest deformation rate, and the magnitude is high. Adhesive tensile strength has a maximum at slightly lower rate than adhesive shear strength has, and has a lower magnitude. Peel strength has a maximum at the lowest deformation rate. These peaks shift toward higher rate side as the relaxation time is lowered, or vice versa.
Our next step is to measure the creep life-time of bonded systems as a function of both temperature and load level, and it is found that the life-time of the bonded materials can be described in a rheological manner. As these kinds of data are accumulated more in future, the theory to predict the life-time of the bonded materials must be refined to a greater extent.
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